U.S. patent application number 10/200086 was filed with the patent office on 2004-01-22 for power tool having a quick-release chuck assembly.
Invention is credited to Levine, David B., Schaub, Bernard.
Application Number | 20040013488 10/200086 |
Document ID | / |
Family ID | 30443479 |
Filed Date | 2004-01-22 |
United States Patent
Application |
20040013488 |
Kind Code |
A1 |
Schaub, Bernard ; et
al. |
January 22, 2004 |
Power tool having a quick-release chuck assembly
Abstract
A tool comprising a housing having a handle and a distal end
wherein the distal end includes a spindle capable of receiving a
bit and defining an axis of rotation. The tool further comprises a
quick-release chuck assembly that includes a sleeve and a trigger.
The sleeve is disposed about the spindle and spring biased in a
locked position wherein the sleeve is capable of being moved
axially to an unlocked position to permit insertion of such a bit.
The trigger includes a finger receiving portion and an actuator
portion where the finger receiving portion extends from the housing
in a position that enables the user to actuate the trigger with a
finger of the hand holding the handle. The actuator portion is in
physical communication with an engagement portion of the sleeve
wherein the activation of the trigger causes the sleeve to move
axially to the unlocked position.
Inventors: |
Schaub, Bernard; (University
Heights, OH) ; Levine, David B.; (Pepper Pike,
OH) |
Correspondence
Address: |
BENESCH, FRIEDLANDER, COPLAN & ARONOFF LLP
ATTN: IP DEPARTMENT DOCKET CLERK
2300 BP TOWER
200 PUBLIC SQUARE
CLEVELAND
OH
44114
US
|
Family ID: |
30443479 |
Appl. No.: |
10/200086 |
Filed: |
July 19, 2002 |
Current U.S.
Class: |
409/239 |
Current CPC
Class: |
Y10T 409/3098 20150115;
B23B 31/1071 20130101; Y10T 408/953 20150115; B25F 5/029 20130101;
Y10T 279/17752 20150115; Y10T 409/306608 20150115; B25F 5/02
20130101 |
Class at
Publication: |
409/239 |
International
Class: |
B23B 045/02 |
Claims
What is claimed is:
1. A tool comprising: a housing having a handle portion and a
distal end portion, said distal end portion includes a spindle
capable of receiving a bit and defining an axis of rotation; and a
quick-release chuck assembly including: a sleeve disposed about
said spindle and spring biased in a locked position of said sleeve,
said sleeve capable of being moved axially to an unlocked position
to permit insertion and removal of such bit in said spindle, said
sleeve being capable of returning to the locked position of said
sleeve, and a trigger having a finger receiving portion and an
actuator portion, said finger receiving portion extends from said
housing in a position enabling the user to actuate said finger
receiving portion of said trigger with a finger of the hand holding
said handle portion of said housing, said actuator portion of said
trigger being in physical communication with an engagement portion
of said sleeve wherein the activation of said finger receiving
portion of said trigger causes said sleeve to move axially to the
unlocked position of said sleeve.
2. The tool of claim 1, wherein said finger is the user's index
finger.
3. The tool of claim 1, wherein said spindle includes a hexagonal
bore for receiving a tool bit having a hexagonal tool shank and a
groove disposed in said tool shank.
4. The tool of claim 3, wherein said quick-release chuck assembly
further includes a ball disposed in a radial bore that is provided
in said spindle, said radial bore being in communication with said
hexagonal bore, said ball being extendible into said hexagonal bore
of said spindle to seat against said groove in said tool bit when
said sleeve is actuated to the locked position.
5. The tool of claim 3, wherein said quick-release chuck assembly
further includes a plurality of balls and a plurality of radial
bores disposed in said spindle wherein each ball is provided in
each radial bore, said plurality of radial bores being in
communication with said hexagonal bore, each of said plurality of
balls being extendible into said hexagonal bore of said spindle to
seat against said groove in said tool bit when said sleeve is
actuated to the locked position.
6. The tool of claim 1, wherein the sleeve is moved axially away
from said distal portion of said housing when the user actuates
said finger receiving portion of said trigger.
7. The tool of claim 1, wherein said engagement portion of said
sleeve comprises at least one ear that extends from an outer
surface of said sleeve.
8. The tool of claim 7, wherein said actuator portion of said
trigger includes a surface that engages said at least one ear when
the user actuates said finger receiving portion of said trigger
thereby causing said sleeve to move axially relative to said
spindle.
9. A quick-release chuck assembly for use in a tool having a
housing that includes a handle portion and a distal end portion,
said distal end portion includes a spindle capable of receiving a
bit and defining an axis of rotation, said quick-release chuck
assembly comprising: a sleeve disposed about said spindle and
spring biased in a locked position of said sleeve, said sleeve
capable of being moved axially to an unlocked position to permit
insertion and removal of such bit in said spindle, said sleeve
being capable of returning to the locked position of said sleeve,
and a trigger having a finger receiving portion and an actuator
portion, said finger receiving portion extends from said housing in
a position enabling the user to actuate said finger receiving
portion of said trigger with a finger of the hand holding said
handle portion of said housing, said actuator portion of said
trigger being in physical communication with an engagement portion
of said sleeve wherein the activation of said finger receiving
portion of said trigger causes said sleeve to move axially to the
unlocked position of said sleeve.
10. The assembly of claim 9, wherein said finger is the user's
index finger.
11. The assembly of claim 9, wherein said spindle includes a
hexagonal bore for receiving a tool bit having a hexagonal tool
shank and a groove disposed in said tool shank.
12. The assembly of claim 11, further comprising a ball disposed in
a radial bore that is provided in said spindle, said radial bore
being in communication with said hexagonal bore, said ball being
extendible into said hexagonal bore of said spindle to seat against
said groove in said tool bit when said sleeve is actuated to the
locked position.
13. The assembly of claim 11, further comprising a plurality of
balls and a plurality of radial bores disposed in said spindle
wherein each ball is provided in each radial bore, said plurality
of radial bores being in communication with said hexagonal bore,
each of said plurality of balls being extendible into said
hexagonal bore of said spindle to seat against said groove in said
tool bit when said sleeve is actuated to the locked position.
14. The assembly of claim 9, wherein the sleeve is moved axially
away from said distal portion of said housing when the user
actuates said finger receiving portion of said trigger.
15. The assembly of claim 9, wherein said engagement portion of
said sleeve comprises at least one ear that extends from an outer
surface of said sleeve.
16. The assembly of claim 15, wherein said actuator portion of said
trigger includes a surface that engages said at least one ear when
the user actuates said finger receiving portion of said trigger
thereby causing said sleeve to move axially relative to said
spindle.
17. A tool comprising: a housing having a handle portion and a
distal end portion, said distal end portion includes a spindle
capable of receiving a bit and defining an axis of rotation; and a
quick-release chuck assembly including: a sleeve disposed about
said spindle and spring biased in a locked position of said sleeve,
said sleeve capable of being moved axially to an unlocked position
to permit insertion and removal of such bit in said spindle, said
sleeve being capable of returning to the locked position of said
sleeve, and a trigger having a finger receiving portion and an
actuator portion, said finger receiving portion extends from said
housing in a position enabling the user to actuate said finger
receiving portion of said trigger with a finger of the hand holding
said handle portion of said housing, said actuator portion of said
trigger being disposed about said sleeve such that activation of
said finger receiving portion of said trigger moves said sleeve
axially to the unlocked position of said sleeve.
18. The tool of claim 17, wherein said sleeve comprises at least
one ear that extends from an outer surface of said sleeve.
19. The tool of claim 18, wherein said actuator portion of said
trigger includes a surface that operatively engages said at least
one ear when the user actuates said finger receiving portion of
said trigger thereby causing said sleeve to move axially relative
to said spindle.
20. The tool of claim 17, wherein said quick-release chuck assembly
further includes a ball disposed in a radial bore that is provided
in said spindle, said radial bore being in communication with said
hexagonal bore, said ball being extendible into said hexagonal bore
of said spindle to seat against said groove in said tool bit when
said sleeve is actuated to the locked position.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to tools and more
particularly to a powered drill for drilling holes using drill bits
and/or power bits having a hex shaped shank.
[0002] Changing drill bits in a drill is a slow, time consuming
procedure that essentially requires three hands. One hand is used
to activate the tool's release mechanism (typically requiring a
movement that requires the use of at least two fingers or a thumb
and a finger), one hand is used to remove and insert a drill bit,
and a third hand is required to hold and stabilize the drill during
the removal/insertion procedure. Because humans only have two
hands, the third hand is usually replaced by holding the drill in
between the user's knees or between the user's arm and chest.
Therefore, this procedure is very time consuming, awkward, and
sometimes results in dropping the drill.
[0003] Accordingly, the present invention provides for a
quick-release chuck assembly that requires only two hands for the
removal/insertion of a drill bit where the release trigger is
within finger's reach of the drill handle and the release trigger
can be activated with a single finger movement. The present
invention also provides for a powered drill that incorporates the
aforementioned quick-release chuck assembly.
SUMMARY OF THE INVENTION
[0004] In one embodiment, the present invention provides for a tool
comprising a housing having a handle portion and a distal end
portion wherein the distal end portion includes a spindle capable
of receiving a bit and defining an axis of rotation. The tool
further comprises a quick-release chuck assembly that includes a
sleeve and a trigger. The sleeve is disposed about the spindle and
spring biased in a locked position wherein the sleeve is capable of
being moved axially to an unlocked position to permit insertion of
such a bit. The trigger includes a finger receiving portion and an
actuator portion where the finger receiving portion extends from
the housing in a position that enables the user to actuate the
trigger with a finger of the hand holding the handle. The actuator
portion is in physical communication with an engagement portion of
the sleeve wherein the activation of the trigger causes the sleeve
to move axially to the unlocked position.
[0005] In another embodiment, the present invention provides for a
quick-release chuck assembly for use in a tool having a housing
that includes a handle portion and a distal end portion. The distal
end portion of the tool includes a spindle capable of receiving a
bit and defining an axis of rotation. The quick-release chuck
assembly comprises a sleeve and a trigger. The sleeve is disposed
about the spindle and spring biased in a locked position wherein
the sleeve is capable of being moved axially to an unlocked
position to permit insertion of such a bit. The trigger includes a
finger receiving portion and an actuator portion where the finger
receiving portion extends from the housing in a position that
enables the user to actuate the trigger with a finger of the hand
holding the handle. The actuator portion is in physical
communication with an engagement portion of the sleeve wherein the
activation of the trigger causes the sleeve to move axially to the
unlocked position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is an exploded perspective view of powered drill 10
according to the present invention;
[0007] FIG. 2 is an exploded perspective view of PCB assembly 34
according to the present invention;
[0008] FIG. 3A is a perspective view of forward-reverse switch 43
and PCB assembly 34 shown in the forward rotation position;
[0009] FIG. 3B is a perspective view of forward-reverse switch 43
and PCB assembly 34 shown in the reverse rotation position;
[0010] FIG. 4 is a perspective view of battery assembly 28
according to the present invention;
[0011] FIG. 5 is a perspective view of drill bit 49;
[0012] FIG. 6A is an exploded perspective view of quick-release
chuck assembly 90 according to the present invention;
[0013] FIG. 6B is an assembled perspective view of quick-release
chuck assembly 90 according to the present invention detailing the
engagement of ears 635 with the inside surface 645 of trigger
605;
[0014] FIG. 7A is a partial front view of powered drill 10
according to the present invention;
[0015] FIG. 7B is a cross-sectional view taken along line Z-Z of
FIG. 7A.
[0016] FIG. 7C illustrates Detail X of FIG. 7B showing the internal
components of quick-release chuck assembly 90 according to the
present invention;
[0017] FIG. 8A illustrates the same view as FIG. 7C in the "locked"
position to prevent the removal of drill bit 49 from spindle
70;
[0018] FIG. 8B illustrates the same view as FIG. 7C in the "locked"
position to prevent the insertion of drill bit 49 into spindle
70;
[0019] FIG. 8C illustrates the same view as FIG. 7C in a position
between the "locked" position and the unlocked position; and
[0020] FIG. 8D illustrates the same view as FIG. 7C in the
"unlocked" position to permit the insertion of drill bit 49 into
spindle 70 or the removal of drill bit 49 into spindle 70.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Referring now to the drawings wherein the showings are for
purposes of illustrating the preferred embodiment of the present
invention only and not for purposes of limiting the same, FIG. 1
illustrates a powered drill 10 that comprises a housing having a
pair of side members 13 defining a tool handle 16 and a motor and
gear housing 19. Nose cap 22 completes the housing of drill 10. A
compact reversible direct current (DC) motor 25 is secured within
the pair of side members 13. The pair of side members 13 are held
together by screws (not shown). A source of electrical energy is
provided to motor 25 from battery assembly 28 located in handle 16.
Cap 31 is located on the end of handle 16 so that battery assembly
28 can be removed and re-installed when needed. Although it is
preferred that the housing components (i.e., pair of side members
13, nose cap 22, and cap 31) be constructed of a lightweight
plastic material, it is contemplated that other materials may used
such as composites, aluminum, steel, stainless steel, alloys, and
combinations thereof.
[0022] Battery assembly 28 and motor 25 are electrically
interconnected through power/polarity control printed circuit board
(PCB) assembly 34 that includes power contacts 205, 210 and
polarity contacts 215, 220 as shown in more detail in FIG. 2.
Polarity contacts 215, 220 are in contact with battery assembly 28
to reverse the polarity of the electrical voltage to motor 25. The
top portion 225 of PCB assembly 34 also includes two pairs of
contacts 230a, 230b and 235a, 235b that when brought together
result in forward or reverse rotation of drill 10, respectively. To
initiate powered operation of drill 10, a manual trigger switch 37
is preferably provided within handle 16 in a position that permits
the user to hold handle 16 in the position of the user's hand and
actuate trigger switch 37 with the user's index finger. Trigger
switch 37 is also provided in handle 16 such that the rear portion
40 of trigger switch 37 is either touching (i.e., in physical
communication) or in close proximity to contact 205 where
activation of trigger switch 37 causes contact 205 to move towards
contact 210. To provide power to drill 10, trigger switch 37 is
activated by the user thereby forcing contact 205 to move in a
direction indicated by arrow A and touch contact 210 to create an
electrical connection. Alternatively, rear portion 40 of trigger
switch 37 may be provided with a bent spring (not shown) such that
when trigger switch 37 is activated, rear portion 40 of trigger 37
switch forces the bent spring to move rearward towards contact 205,
which forces contact 205 to move towards contact 210. Once contact
205 is touching contact 210, an electrical connection is made
thereby powering drill 10. In another embodiment, a first portion
of the bent spring may be provided between contacts 205 and 210
such that activation of trigger switch 37 forces a second portion
of the bent spring into contact with contact 205 which then
contacts the first portion of the bent spring. The first position
of the bent spring then touches contact 210 thereby making an
electrical connection to initiate power to drill 10.
[0023] To control the polarity of the output voltage to selectively
reverse the operation of motor 25, forward-reverse switch 43
preferably extends from housing 25 in a position that permits the
user to hold handle 16 in the position of the user's hand and
activate forward-reverse switch 43 with the user's thumb.
Forward-reverse switch 43 is movable between a forward rotation
position (see FIG. 3A) and a reverse rotation position (see FIG.
3B). Preferably, the actuation of switch 43 by the user in the
forward direction as indicated by Arrow B shown in FIG. 3A
corresponds to the forward rotation position while the actuation of
switch 43 in the rearward direction as indicated by Arrow C shown
in FIG. 3B corresponds to the reverse rotation position.
Forward-reverse switch 43 is coupled to actuator 46 having pin 240
which is sliding engaged in slot 245 of switch 43. Thus, actuation
of switch 43 creates pivotal movement that is translated to
actuator 46 thereby causing actuator head 250 to slide along the
top portion 225 of PCB assembly 34 and force contacts 230a or 235a
to meet 230b or 235b, respectively. In operation, when the user
urges switch 43 to the forward rotation position as shown in FIG.
3A, actuator head 250 slides in the direction indicated by arrow Z
and forces contacts 230a to touch contacts 230b as indicated by
arrow D. Since polarity contact 220 is in electrical communication
with contacts 230b, and since polarity contact 220 is in electrical
communication with battery assembly 28, then the electrical circuit
is complete for forward rotation of drill 10. Alternatively, when
the user urges switch 43 to the reverse rotation position as shown
in FIG. 3B, actuator head 250 slides in the direction as indicated
by arrow Y and forces contacts 235a to touch contacts 235b as
indicated by arrow E. Likewise, since polarity contact 215 is in
electrical communication with contacts 235b and since polarity
contact 215 is in electrical communication with battery assembly
28, then the electrical circuit is complete for reverse rotation of
drill 10. In this manner, the user may selectively reverse the
direction of motor rotation thereby controlling the direction of
drill bit rotation to permit the advance or removal of drill bit 49
as appropriate.
[0024] As shown in FIG. 4, battery assembly 28 comprises batteries
400 that are stored in a retainer housing 405 that is removable
from tool handle 16 by removing cap 31 and sliding out retainer
housing 405. Retainer housing 405 includes a hinged door 410 that
is capable of being snapped into place thereby retaining batteries
400. Preferably, retainer housing 405 also includes a hole 415 and
slot or groove 420 for storing one or more drill bits 49. To store
drill bit 49, preferably the tip 425 of drill bit 49 is first
inserted into hole 415 and then the groove 430 in the shank of
drill bit 49 is than snapped into the slot 420. Although only one
hole and slot is shown in FIG. 4, it is contemplated that two or
more sets of holes and slots may be provided on retainer housing
405 to store two or more drill bits. Further, other means known in
the art may be provided on retainer housing 405 to store one or
more drill bits 49.
[0025] Preferably, the source of electrical energy to power drill
10 is battery assembly 28 comprising six alkaline batteries.
Although alkaline batteries are preferred, it may be obvious to one
skilled in the art that other battery types are within the scope of
the present invention. Also, although six alkaline batteries are
utilized in the preferred embodiment, it is obvious that at least
one battery or more than six batteries may be used. Additionally,
the source of electrical energy to power drill 10 may be AC voltage
that would also require a motor capable of being powered with AC
voltage and a power cord to plug into a standard AC wall
receptacle.
[0026] Although the present invention provides a powered drill 10,
it is obvious to one skilled in the art that powered drill 10 may
be utilized as a powered screwdriver. Accordingly, instead of
utilizing drill bits 49, the user would utilize power bits having
various head designs such as phillips, flat head, or other
appropriate power bits in common usage. Such drill bits or power
bits would include a hexagonal shank and a circumferentially
extending groove. As shown in FIG. 5, drill bit 49 includes a
hexagonal shank 502 and a radially inwardly extending
circumferential groove 504. The groove 504 is of a predetermined
width and a predetermined depth. The groove 504 includes a pair of
radius portions 506 and 508, and a bottom flat 510 between the
radius portions 506 and 508. At the rear end of the drill bit 49 is
a rear face 514. Between the groove 504 and the rear face 514 is a
rear shank portion 512.
[0027] As shown in FIG. 1, motor 30 includes an armature shaft (not
shown) that has motor pinion gear 52 mounted thereon. Motor speed
is reduced through a series of gear reduction stages. Stage one
gear reduction includes gear 55 having a shaft with pinion gear 58
mounted thereon. Gear 55 engages pinion gear 52. Stage two gear
reduction includes gear 61 having a shaft 64 with pinion gear 67
mounted thereon wherein gear 61 engages pinion gear 58. Preferably,
the gear speed reduction is approximately 24:1.
[0028] Drill 10 further comprises a spindle 70 that includes a
cylindrical outer surface 73 at one end having a hex-shaped
internal bore 76 for receiving drill bit 49 and a gear 79 at the
other end that engages pinion gear 67. Drill bit 49 defines an axis
of rotation, A'. Intermediate the hex-shaped internal bore 76 and
gear 79 is a shaft portion 82. Shaft bushing 85 and shaft bushing
88 encompass the shaft portion 82 of spindle 70 and are provided as
a bearing surface. Shaft bushing 85 also includes a bearing for
receiving shaft 64.
[0029] One important feature of the present invention is a unique
quick-release chuck assembly 90 integrated within drill 10 that
utilizes a trigger located near power trigger 45 to actuate the
quick-release chuck assembly. Typically, in a prior art
quick-release chuck assembly, a sleeve capable of being actuated by
the user in an axial direction in order to quickly remove a drill
bit and replace it with a different bit. In these prior art
quick-release chuck assemblies, the user actuates the sleeve with
his/her fingers wherein the user slides the sleeve axially under
resistance of a spring from a locked position of the sleeve to an
unlocked position of the sleeve. Releasing the sleeve allows the
sleeve to move back to the locked position under influence of the
spring. As used in the claims, the term "quick-release chuck
assembly" is intended to include a sleeve that is capable of being
actuated in an axial direction in order to quickly remove/insert a
drill bit and a finger activated trigger or actuator that is
operably connected to the sleeve-thereby causing the sleeve to move
axially when the trigger is activated. The position of the trigger
or actuator provides for easy activation without leaving go of the
handle while the prior art quick-release chuck assemblies require
the user to release their grip on the handle in order to activate
the sleeve with their fingers. The locked position may be forwardly
disposed and the unlocked position may be rearwardly disposed,
although some quick-release chuck assemblies work just the opposite
(locked and spring biased rearwardly and unlocked forwardly). The
claims are intended to cover both arrangements.
[0030] As shown in FIGS. 6A and 6B, the quick-release chuck
assembly 90 comprises a release trigger 605, sleeve 610, ball 615
disposed in bore 617 of spindle 70, and spring 620. Preferably,
release trigger 605 includes a finger receiving portion 625 that
extends from the bottom portion 93 of the motor and gear housing 19
and is within reach of the same index finger used to activate the
on-off trigger switch 37 and an actuator portion 630 to cause
sleeve 610 to move in an axial direction when finger receiving
portion 625 is activated by the user. Sleeve 610 is also situated
in the motor and gear housing 19 in a movable relationship with
release trigger 605 such that actuation of release trigger 605
causes sleeve 610 to move in an axial direction relative to spindle
70. Sleeve 610 is disposed about spindle 70 and includes an
engagement portion such as ears 635 that project outwardly away
from sleeve 610. Trigger 605 includes an opening 640 provided in
actuator portion 630 of trigger 605 to receive sleeve 610 and is
positioned within housing 19 such that an inner surface 645 (i.e.,
corresponding engagement portion) adjacent opening 640 in trigger
605 is either touching (i.e., in physical communication) or in
close proximity with ears 635 on sleeve 610. Accordingly, when
trigger 605 is actuated, trigger 605 pivots about pivot point 490
where the pivotal movement of trigger 605 causes sleeve 610 to move
in an axial direction relative to spindle 70 when the inner surface
645 of trigger 605 contacts ears 635 on sleeve 610. One skilled in
the art would appreciate that the engagement portion of sleeve 610
may take the form of any male-type structure and the corresponding
engagement portion of trigger 605 may take the form of any
structure that provides for a movable relationship between the two
parts (i.e., sleeve 610 and trigger 605) and is within the scope of
the present invention. Alternatively, trigger 605 may include the
male-type structure where sleeve 610 takes the form of a
corresponding engagement portion. Further, one skilled in art would
recognize that there are many designs to operably connect sleeve
610 to trigger 605 such that activation of trigger 605 moves sleeve
610 in an axial direction relative to spindle 70 and these designs
are within the scope of the present invention
[0031] By providing release trigger 605 within index finger's reach
of the power trigger 45, the user is able to change drill bit 49
with one hand without releasing his/her grip on handle 16 with the
other hand. It is also important to note that the quick-release
chuck assembly according to the present invention may be provided
in any tool that utilizes changeable bits such as a screwdriver,
power screwdriver, power drill, power saw, or other power tool. In
this context, changeable bits may include power bits, drill bits,
or saw blades.
[0032] FIG. 7C illustrates the quick-release chuck assembly 90 in
detail. As shown in FIG. 7C, spindle 70 includes a front end 705,
which defines a front face that is generally perpendicular to the
longitudinal axis of the spindle 70. Extending rearwardly from the
front end or front face 705 is the internal bore 76. Internal bore
76 is illustrated as being of a hexagonal configuration, but may be
of other configurations that prevent rotation of the shank 502 bit
49 in bore 76. Preferably, drill bit 49 includes a hexagonal shank
502 which is adapted to be received into, or to extend into,
hexagonal bore 76. The longitudinal axis of bore 76 is
substantially aligned with the longitudinal axis of spindle 70.
Bore 76 includes a rear end 710 that defines a rear face which is
substantially perpendicular to the longitudinal axis of bore 76 and
is substantially parallel to the front end or face 705 of spindle
76.
[0033] Intermediate the front face 705 and the rear face 710 of
spindle 70 is a radially extending bore 617 that extends through
cylindrical surface 73 of spindle 70 and communicates with bore 76.
At the juncture of bores 76 and 617 is a retainer lip 720 that
extends inwardly to decrease the diameter of radial bore 617. Ball
615 is disposed in bore 617 and is retained in bore 617 by retainer
lip 720, or is prevented from falling out of bore 617 by retainer
lip 720. However, as shown in FIG. 7C, lip 720 allows ball 615 to
extend a substantial distance into bore 76. The diameter of ball
615 is slightly less than the diameter of radial bore 617. There is
accordingly very little side-to-side movement of ball 615. However,
ball 615 moves radially in bore 617, as will be discussed below.
Further, one skilled in the art would appreciate that more than one
radial bore 617 accepting more than one ball 615 may be provided
within spindle 70.
[0034] Sleeve 610 includes a front end face 725 that is
substantially perpendicular to the longitudinal axis of spindle 70.
Parallel to front end face 725 is a rear end face 730. Within
sleeve 610 is a rear bore 745 that extends frontwardly from rear
face 730 of sleeve 610. The diameter of bore 745 is slightly larger
than that of cylindrical surface 73 of spindle 70. Extending
frontwardly from rear bore 745 is front bore 750. The diameter of
the front bore 750 is greater than that of rear bore 745 to permit
a portion of ball 615 to move into the increased space created by
bore 750.
[0035] The diameter of ball 615 is substantially greater than the
thickness of the cylindrical surface 73 of the spindle 70 through
which radial bore 617 extends. It follows that the diameter of bore
617 is greater than the overall length of bore 617. Ball 615
accordingly extends partially out of bore 617 and into bore 750 of
the sleeve 610, and partially into hexagonal bore 76 of the spindle
70.
[0036] A compression spring 620 is provided over the shaft portion
82 of spindle 70 between shaft bushings 85, 88 and rear end face
730 of sleeve 610. Preferably, one end of spring 620 is seated
against a rib 75 provided on bushings 85, 88 and the other end of
spring 620 is provided against rear end face 730. Spring 620 is
disposed about the cylindrical surface 73 of spindle 70 and a
portion of shaft bushings 85, 88. Spring 620 biases sleeve 610
frontwardly away from rib 755 provided on bushings 85, 88.
[0037] It will be noted that compression spring 620 need not be a
very strong spring. A relatively light spring is sufficient to
provide the necessary bias between sleeve 610 and spindle 70, and
against ball 620, to securely lock drill bit 49 within internal
bore 76 of drill 10. The frictional and normal forces applied are
sufficient to cause drill bit 49 to be locked or held securely in
bore 76. In actuality, the greater the longitudinally outward pull
on drill bit 49, the greater are the lockup forces acting through
ball 620 between spindle 70 and sleeve 610 against the radius 504
of drill bit shank 502 to secure drill bit 49 within bore 76.
[0038] Trigger 605 and thus sleeve 610 is movable between a
"locked" position where a drill bit 49 cannot be removed or
inserted and an "unlocked" position where a drill bit 49 may be
inserted or removed. FIGS. 8A-8B illustrate quick-release chuck
assembly 90 in the "locked" position. When release trigger 605 is
in its normal state (i.e., not being actuated by drill user), drill
10 is in a "locked" position meaning that drill bit 49 cannot be
removed if a bit is present or a drill bit 49 cannot be inserted if
a drill bit is not present. In a "locked" position as shown in FIG.
8A, spring 620 urges sleeve 610 frontward as shown in FIG. 8A such
that ball 615 is situated in bores 76 and 617. Thus, when a drill
bit 49 is present in bore 76, ball 615 is forced into groove 504
and against radius 508 of drill bit shank 502 thereby locking drill
bit 49 in place. The contact between sleeve 610, ball 615, and
drill bit 49 causes both frictional and normal forces to act on
drill bit 49 to hold drill bit 49 securely in bore 76 of spindle
and to prevent movement of drill bit 49 within bore 76. As shown in
FIG. 8B, when a drill bit 49 is not present, ball 615 is situated
partially in bore 76 which will prevent a drill bit 49 from being
inserted.
[0039] FIG. 8C illustrates quick-released chuck assembly 90 in the
"in-locked" position. When release trigger 605 is actuated by the
user, drill 10 is in an "unlocked" position meaning that drill bit
49 can be inserted or removed. In order to insert or remove drill
bit 49 from bore 76, release trigger 605 is actuated by the user's
finger in the direction as indicated by arrow F in FIG. 6B.
Preferably, the finger is the user's index finger that also
actuates the on-off trigger switch 37. To operate quick release
chuck assembly 90, the user begins to actuate trigger 605 causing
trigger 605 to pivot about pivot point 490. As trigger 605 pivots
about pivot point 490, the inside surface 645 of trigger 605 forces
sleeve 610 (via contact with ears 635) to move in a rearward axial
direction indicated by Arrow G against the bias of spring 620
thereby compressing spring 620 such that bore 750 is moving closer
to be aligned with bore 617 as shown in FIG. 8C. When bore 750
begins to line up with bore 617, ball 615 begins to drop out of
bore 76 and begins to partially drop into bore 750 as indicated by
Arrow H. Upon full actuation of trigger 605, ball 615 completely
clears bore 76 and rests fully in bores 617 and 750 allowing the
user to freely insert a new drill bit 49 or remove an existing
drill bit 49 as shown in FIG. 8D. After drill bit 49 is removed
from bore 87, sleeve 610 may be returned to its normal state (i.e.,
locked position) by releasing trigger 605, and ball 615 will move
back upwardly into radial bore 617 and partially back into
hexagonal bore 76.
[0040] Although the invention has been shown and described with
respect to certain embodiments, it is obvious that equivalent
alterations and modifications will occur to others skilled in the
art upon reading and understanding of the specification. The
present invention includes all such equivalent alterations and
modifications.
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